Anionic bituminous emulsions

ABSTRACT

There is disclosed herein oil-in-water anionic bituminous emulsions which comprise from about 30% to about 75% by weight of the emulsion of bitumen as the dispersed phase, and from about 0.1% to about 10.0% by weight of an anionic emulsifier consisting of an oxygenated alkali lignin, an ethylene oxide adduct of phenol, and 0% to about 10% by weight of sodium borate and water in an amount to make up 100% by weight as the continuous phase.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to improvements in oil-in-water anionicbituminous emulsions. More particularly, this invention relates to theproduction of oil-in-water anionic bituminous emulsions with the aid ofa particular anionic emulsifying agent comprising an alkali lignin andan ethylene oxide adduct of an alkyl phenol.

2. The Prior Art

Aggregates for road building are generally coated with suitable asphaltmixes which include bitumens which affect the coating of the aggregates.The aggregates used are, of course, sand, gravel and other suitable andwell known aggregates.

To prevent the emulsion from leaving the aggregate, known as"stripping", the asphalt mixes are provided with additives which areusually of either cationic or anionic surfactants. Formulators arecontinuously attempting to use more effective surfactants of both thecationic and anionic varieties. Although satisfactory results can beobtained with certain types of both surfactants, certain deficiencies,both as to performance and price, leave room for considerableadvancement in this field.

The use of lignin-type materials, specifically lignin amines for use inanionic bituminous emulsions, are disclosed in U.S. Pat. No. 3,123,569to M. J. Borgfeldt. Further, it is also known to use ethers formed fromethylene oxide and nonyl phenol as surfactants in bituminous emulsionsas disclosed in U.S. Pat. No. 3,366,500 to Kracauer. However, no one hasshown the advantages obtained by the use of an ethylene oxide adduct ofnonyl phenol together with the particular lignin materials of thisinvention in anionic bituminous emulsions.

Accordingly, it is a general object of the present invention to providean anionic emulsion for coating aggregates for road building and thelike.

Another object of the present invention is to provide an anionicbituminous emulsion for coating aggregates for road building and thelike which has universal action, that is, it can be used for alldifferent types of asphalt mixes for the coating of all different typesof aggregate.

Other objects, features and advantages of the present invention will beapparent from the foregoing detailed description of the invention.

SUMMARY OF THE INVENTION

It has been found that oil-in-water anionic bituminous emulsions capableof producing satisfactory, mechanically stable mixes with aggregates maybe effectively prepared by employing from about 30% to about 75% byweight of the emulsion of bitumen as the disperse phase, from about 0.1%to about 10.0% by weight of an anionic emulsifier comprising an alkalilignin and an ethylene oxide adduct of alkyl phenol in a weight ratio of10:1 to 1:10 of lignin to alkyl phenol adduct, from 0% to 10% sodiumborate, with the remainder being water as the continuous phase.

DETAIL DESCRIPTION OF THE INVENTION

The anionic emulsifier used in the continuous phase of the oil-in-wateremulsions of this invention comprises, a mixture of alkali lignin andether formed from ethylene oxide and alkyl phenol in a weight ratio offrom 10:1 to 1:10 of lignin to alkyl phenol adduct.

The lignins employed in the anionic emulsifier used in this inventioninclude alkali lignins from the sulfate (kraft) pulping process, andlignins derived from other alkaline pulping processes, such as soda ormodified soda processes. Alkali lignins that have been modified byoxygenation or oxidation may also be used. The lignins may be modifiedby bubbling oxygen or air through a solution of alkali lignin at pH 10to 13 and a temperature of 50°C. to 100°C.

The other necessary portion of the anionic emulsifier is the adductformed from the reaction of ethylene oxide and an alkyl phenol. Alkylphenols are contemplated to include nonyl phenol, octyl phenol anddodecyl phenol, with nonyl phenol being preferred. The adduct maycontain from 10 to 100 moles of ethylene oxide per mole of nonyl phenol,but preferably contains from 30 to 50 moles of ethylene oxide per moleof nonyl phenol.

As stated, the lignin and alkyl phenol adduct are in a weight ratio of10:1 to 1:10 of lignin to alkyl phenol adduct, preferably the ratio isbetween 7:3 and 4:6 by weight lignin to alkyl phenol adduct.

In preparing the bituminous emulsions of this invention, an aqueousanionic emulsifying solution prepared as described hereinbelow isintimately contacted with a suitable bitumen by a mixing device, such asa colloid mill, which is capable of producing a vigorous shearingaction. The bitumen content of the emulsion can range from about 30% toabout 75% by weight of the emulsion depending upon the intended use,preferably about 55% to about 65% by weight. The anionic emulsifier ispresent in the final emulsion in a concentration ranging from about 0.1%to about 10.0% by weight of the emulsion, preferably about .5% to about3.0% by weight of the emulsion. Additionally, it may be desirable to addup to 10% by weight of the emulsion, preferably about 1.0% to 5.0%, ofsodium borate (borax). It is also desirable to adjust the pH of theemulsion to between 10 and 12, preferably 10.5 to 11.5. Further, it alsomay be desirable when preparing the anionic emulsifier as a liquid,which may contain, for example, a 40% solids concentration, to add up toabout 20% by weight of a lower alkyl alcohol having less than 6 carbonatoms, for example, isopropanol, ethanol, etc., which assists in forminga stable emulsifier.

The "bitumen" used in the emulsion may be derived from Venezuela,Mid-Continent, Western and other bitumen sources and also includes, inaddition to bitumen, natural asphalt, petroleum oil, still residues ofpaving grade, plastic residues from coal tar distillation, petroleumpitch, petroleum resins, solutions of such substances like cut-backasphalt, and the like. Practically any asphalt penetration valuesranging from about 40 to about 300 may be emulsified with the aid of theanionic emulsifiers of this invention.

The practice of this invention may be seen in the foregoing exampleswherein the anionic emulsifier was used to illustrate its advantages inan oil-in-water anionic bituminous emulsion. In each these examples, thetests were performed according to ASTM D-244.

EXAMPLE 1

This example shows a series of emulsions using an alkali lignin, IndulinC, a product of Westvaco Corporation, as the lignin component in theemulsion and various nonyl phenol adducts. As will be seen in the table,a number of emulsions were prepared using varying weight ratios of thelignin to the ethylene oxide adduct of nonyl phenol, see Emulsion 1 andEmulsion 7 through 10 wherein the weight ratio of lignin to ethyleneoxide adduct of nonyl phenol was varied between 50/50 and 80/20.Emulsions 1 through 3 show emulsions prepared with ethylene oxide adductof nonyl phenol having various mole additions of ethylene oxide varyingfrom 9.5 to 50 moles of adduct. Additionally, the emulsions wereprepared at additive levels of .1% up to 1.25% by weight of the totalemulsifier which was added to an asphalt, in Emulsions 1 through 3,Humble Asphalt (120/150 penetration value) and in the remainingemulsions of Venezuelian Asphalt (120/150 penetration value). Emulsion 6was run showing the addition of borax at a 5% level. The results ofthese emulsions are shown in the table below.

                                      TABLE I                                     __________________________________________________________________________                Formulation     Sieve                                             Emulsion                                                                           Asphalt                                                                              Lignin/Nonyl    Test, %                                                                             Evap. %                                                                             Cement                                No.  Used   Phenol Adduct                                                                           %     Residue                                                                             Residue                                                                             Test                                  __________________________________________________________________________         Humble                                                                   1    120/150                                                                              50/50     1.0   .06   62.4  pass                                       Humble                                                                   2    120/150                                                                              50/50     1.0   .03   62.5  pass                                       Humble                                                                   3    120/150                                                                              50/50     1.0   .04   62.7  pass                                       Ven.                                                                     4    120/150                                                                              60/40     1.25  .06   65.4  pass                                       Ven.                                                                     5    120/150                                                                              60/40     1.25  .03   65.6  pass                                       Ven.   60/40                                                             6    120/150                                                                              5.0%.sup.+ Borax                                                                        1.25  .03   63.5  pass                                       Ven.                                                                     7    120/150                                                                              80/20     1.25  0.5   62.3  pass                                       Ven.                                                                     8    120/150                                                                              70/30     1.25  0.5   62.4  pass                                       Ven.                                                                     9    120/150                                                                              60/40     1.25  0.1   63.5  pass                                       Ven.                                                                     10   120/150                                                                              70/30     1.50  0.5   62.2  pass                                  __________________________________________________________________________         Viscosity                                                                             Particle         Pumping                                         Emulsion                                                                           Saybolt Charge                                                                              pH         Test Emulsion                                   No.  Sec. at 77°F.                                                                  Test  Soln.                                                                             Formulation                                                                          (sec.)                                                                             pH   Comments                              __________________________________________________________________________    1    --      Negative                                                                            --  --     --   --   --                                    2    ≦                                                                              Negative                                                                            --  --     --   --   --                                    3    --      Negative                                                                            --  --     --   --   --                                                 8→6.6 ma                                                  4    51.5    wash off                                                                            10.5                                                                              9.75   --   --   --                                                 8→6.85ma                                                  5    56.2    wash off                                                                            10.6                                                                              9.9    --   --   --                                                 8→7.6 ma                                                  6    34.0    no wash                                                                             10.5                                                                              10.05  --   --   --                                                 off                                                                           8→7.35ma                                                  7    39.8    no wash                                                                             --  --      60  10.6 slightly                                           off                        grainy                                             8→6.8 ma                                                  8    31.3    no wash                                                                             --  --     120  10.6 slightly                                           off                        grainy                                             8→7.6 ma                                                  9    34.0    no wash                                                                             --  --      420+                                                                              10.0 slightly                                           off                        grainy                                             8→7.8 ma                                                  10   38.9    no wash                                                                             --  --     120  10.5 slightly                                           off                        grainy                                __________________________________________________________________________

The results shown in the table show that satisfactory anionic asphaltemulsions can be made with the anionic emulsifier of the subjectinvention.

EXAMPLE 2

This example illustrates emulsions made varying the weight of nonylphenol adduct to lignin and showing in some cases the effect of theaddition of borax on pumping time. It is also shown by this example andin the results in the table the effect of using an oxylignin in place ofthe alkali lignin, Indulin C.

The emulsions were made with 120/150 penetration Venezuelian asphaltusing an emulsifier dosage of 1.0% at pH 11.0 and an asphalt level of62%. The pumping time results were:

                  TABLE II                                                        ______________________________________                                        Weight Ratio         Pumping Time                                             ______________________________________                                                        Nonyl                                                         Lignin*                                                                              Borax    Phenol Adduct                                                                              Minutes Seconds                                  ______________________________________                                        70     0        30           3'      30"                                      65     0        35           4'      40"                                      60     0        40           4'      30"                                      60     5        35           7'      00"                                      55     5        40           37'     00"                                      55     10       35           9'      20"                                      56     5        39           22'     30"                                      **60   0        35           24'     00"                                      ______________________________________                                         Notes:                                                                        *Formulations were prepared with spray dried Indulin C.                       **Formulation made with an oxylignin.                                    

The results clearly show the effect of the addition of sodium borate tothe emulsion ratio and its increase on pulping time. Also, theeffectiveness of the oxylignin is shown in the results in the table asillustrated by the lengthy pulping times obtained.

While the invention has been described and illustrated herein byreferences to various specific materials, procedures, and examples, itis understood that the invention is not restricted to the particularmaterials, combinations of materials, and procedures selected for thatpurpose.

What is claimed is:
 1. An oil-in-water anionic bituminous emulsion whichcomprises,a. from about 30% to about 75% by weight of the emulsion ofbitumen as the disperse phase, b. from about 0.1% to about 10.0% byweight of an anionic emulsifier consisting of an oxygenated alkalilignin produced by bubbling oxygen or air through a solution of alkalilignin at a pH between 10 and 13 and at a temperature of 50°C to 100°Cand an ethylene oxide adduct of an aklyl phenol in a weight ratio of10:1 to 1:10 of lignin to an alkyl phenol adduct, and from 0% to about10% by weight sodium borate, and c. water in an amount to make up 100%by weight as the continuous phase.
 2. An oil-in-water anionic emulsionas defined in claim 1 wherein said bitumen is asphalt in an amount fromabout 55% to about 65% by weight.
 3. An oil-in-water anionic emulsion asdefined in claim 1 wherein the pH of the emulsion is adjusted to betweenabout 10 and 12 prior to using.
 4. An oil-in-water anionic emulsion asdefined in claim 1 wherein said anionic emulsifier is present in anamount from about 0.5% to about 3.0% and said lignin to alkyl phenoladduct ratio is between 7:3 and 4:6 by weight.
 5. An oil-in-wateranionic emulsion as defined in claim 1 wherein said alkyl phenol isnonyl phenol and the adduct contains from 10 moles to 100 moles ofethylene oxide.
 6. An oil-in-water anionic emulsion as defined in claim1 wherein said nonyl phenol adduct contains from 30 moles to 50 moles ofethylene oxide.
 7. An oil-in-water anionic emulsion as defined in claim1 wherein said sodium borate is present in an amount from about 1% toabout 5% by weight.